Electrolytic deposition of metals



Sept. 28 1926.

Filed August 20 192 M. M. MERRITT ELECTROLYTIC DEPOSITION OF METALS 5 Sheets-Sheet Sept. 28 1926.

1,601,692 M. M. MERRITT ELECTROLYTIC DEPOSITION OF METALS Filed August 20 1925 3 Sheets-Sheet 2 Vina/e wife a" mi wwnmrra'ii Z1 22 MZWV W5 Sept. 28, 1926. 1,601,692

M. M. MERRITT ELECTROLYTIC DEPOSITION 0F METALS Filed August 1925 s Sheets-Sheet 5 Patented Sept. 28, 1926. 1,601,692

UNITED STATES PATENT OFFICE.

MATTHEW M. MERRITT, F MIDDLETON, MASSACHUSETTS, ASSIGNOR TO INDUSTRIAL DEVELOPMENT CORPORATION, OF PORTLAND, MAINE, A CORPORATION OF MAINE.

ELECTROLYTIC DEPOSITION OF METALS.

Application filed August 20, 1925. Serial No. 51,379.

My invention pertains to electrolytic appaproximity to the cathode surface. The ratus and particularly but not exclusively level of the liquid in the trough is mainto apparatus for making sheet metal by tained substantially horizontal, that is to electro-deposition. say, parallel to the axis of the drum 1, by

My invention will be best understood from means of a dam 20 having a lower opening 00 the following description when read in light 21 through which the major portion of the of the accompanying drawings of one speelectrolyte passes, the remaining small porcific embodiment of my invention selected tion of the electrolyte flowing over the dam for illustrative purposes, while the scope of by way of a notch 22 formed in its upper my invention will be more particularly edge. 68 pointed out in the appended claims. The electrolyte leaving the trough 17 dis- In the drawings: charges into a trough 23 from which trough Figure 1 is a plan View of apparatus arit discharges through a pipe 25 leading to ranged according to my invention; and a pump 27, which pump forces the electro- Figs. 2, 3, 4 and 5 are respectively sections lyte through a pipe 29 to one end of a con- 7 on the lines 22, 33, 4-4 and 55 of duit or tank 31. In the tank 31 is a verti- Fig. 1, Figs. 3, 4 and 5 being on an enlarged cally movable container 33 for metal-bearing scale, and Fig. 2 in addition showing more material 35 for replenishing the electrolyte. or less diagrammatically mechanism for The material 35 may be in any suitable form,

raising and lowering the container for the as for example if copper is to be deposited Y5 metal-bearing electrolyte replenishing ma on the cathode 5 it may be copper ore, suitterial. able salts of copper, or sheet copper scrap, Referring to the drawings I have shown a preferably the latter. The walls of the concylindrical drum 1 rovided with frustotainer 33 are perforated as is indicated at 36 conical ends 3, the (ii'um being formed of for permitting passage therethrough of the 8 wood, porcelain or other suitable non-con electrolyte.

ducting material and carrying intermediate The electrolyte discharges from one end its length an endless sheet 5 of copper or of the tank 31through orifices 37 into a other suitable conductive metal serving as downwardly inclined chute 38 provided with a cathode on which the metal sheet to be baffles 39 for thoroughly mixing the elec- 95 formed is deposited from the electrolyte trolyte. The chute 38 discharges the elec- The length of the cathode corresponds to trolyte into a distributing trough 41 with the width of the sheet which is indicated at which may communicate any number of 7. As the sheet 7 is deposited on the cathode troughs 17, only one of which however is it is stripped therefrom by means of a roshown in the drawings. For giving the tating drum 9, the surface of the cathode electrolyte considerable velocity as it passes being treated with mercury to form thereon through the troughs 17 between the cathode a coating 10 of amalgam to facilitate the and anode surfaces the chute connecting the stripping operation. For rotating the trough 41 with the trough 17 at its bottom is drums 1 and 9 and thus stripping the sheet in the form of an apron 43. The amount of from the former and winding it upon the electrolyte entering the trough 17, if a plulatter the drums are respectively carried on rality of troughs 17 are provided, is conshafts 11 and 13 which are slowly rotated trolled by a suitable gate 44, it being underby suitable mechanism not necessary to be stood of course that if but one trough 17 is described herein. provided use of the gate 44 will be unneces- The drum 1 conveniently is in contact sary.

to a depth of approximately one-third its In practice the positive terminal of a diameter with a swift-flowing continuous suitable source of electromotive force is stream of electrolyte the level of which is connected to the anode constituted by the 60 indicated at 15 in Fig. 2. The electrolyte insoluble lining 19 of the trough while the flows by the drum in a trough 17 having a negative terminal is connected to the cathode lining 1.9 of lead or other suitable conduc- 5 by means herein conventionally illustrated tive metal insoluble in the electrolyte, conas a brush 45 (Fig. 2) in contact with a stitut-ing an anode, the surface of which is conducting disk 46 mounted on the shaft 11 55 uniformly distributed in relatively close which shaft is placed in electrical communication with the cathode by means of a conductor 47. The metal-bearing material 35 in the container 33 is maintained at substantially the same potential as the insoluble lining 19 of the trough by reason of the fact that the electrolyte constitutes a conductor placing the two in electrical communication. I have found that by impressing sufficient potential on the metal-bearing material 35 that the same will enter into solution in the electrolyte and by suitably proportioning the amount of surface of metalbearing ma terial to the amount of electrolyte acting in a given time upon said surface I am thus enabled to effect replacement in the electrolyte of the metal deposited therefrom on the cathode 5. This method of replenishing the electrolyte discovered by me is applicable to all metals lower than hydrogen in the electromotive series. When depositing copper on the cathode I preferably employ as electrolyte a copper sulphate solution with a lower percentage of free sulphuric acid, sheet copper scrap being used for the elec trolyte replenishing material, and I have found that best results can be obtained when the impressed potential on the insoluble lining of the trough and copper scrap is not less than one and one-half volts.

The present application is particularly concerned with the regulation of the metal content or specific gravity of the electrolyte, whicli preferably is done by maintaining the amount of metal in solution between predetermined limits. \Vhen depositing copper on the cathode I have found that satisfactory results can be obtained when the metal content is maintained between limits of 26 and 32 ounces of copper sulphate crystals per gallon of electrolyte, the sulphuric acid concentration at these limits being respectively 10 and 6 percent, corresponding to electrolyte specific gravities at these limits of metal and acid content of respectively 1.18 and 1.24:.

In the present application for the purpose of controlling the metal content of the electrolyte I provide means for raising and lowering the container 33 containing the metal-bearing material relatively to the tank 31 so as to move all or a portion of the metal-bearing material in and out of the electrolyte with the result that both the amount of surface of metal-bearing material and amount of electrolyte subjected to each other are varied. To this end the container 31 is suspended by means of a cable 48 wound about a rotating drum 49, the shaft 51 of the drum carrying a worm wheel 53 meshing with a worm 55 carried by the shaft of a reversible electric motor 57.

For controlling the electric motor 57 I have shown a reversing switch comprising a pair of switch arms 59 cooperating with three contacts 61, the outer contacts of which are connected to one terminal of the motor, while the central contact is connected to the other terminal of the motor. The switch arms which respectively are connected to opposite sides of a suitable source of electro-motive force are pivoted at 63 and for simultaneous movement are pivotally connected intermediate their length by a bar 65 of insulating material.

The reversing switch may be operated manually but as illustrated it is operated automatically by a hydromcter or float actuated mechanism 66 situated at the discharge end of the trough 38 in response to changes in specific gravity of the electrolyte which is a direct function of the metal content of the electrolyte. To this end I provide the bar 65 connecting the switch arms 59 of the reversing switch with armatures (37. the latter cooperating with a pair of solenoid coils 69 so that when one or the other of the solenoids is energized by the rise or fall of the hydrometer the switch arms will be moved to their extremes of movement to effect rotation of the motor 57 in one or the other of opposite directions causing raising or lowering of the container 33 for the electrolyte replenishing material. IVhen both solenoids are deenergized springs 71 hold the switch arms in neutral position and no rotation of the motor takes place.

The hydrometer or float actuated mechanism 66 comprises a float 75, this float rising with an increase of metal content of the electrolyte and falling with a decrease of metal content. The stem 77 of the float (Fig. 4) carries a block of insulating material '79 which carries a ring contact 81 arranged to cooperate with spring contacts 83 and 85. The block 79 is attached to the stem 77 by means of a rod 87 which is screw threaded into the end of the stem 77, thus permitting the distance between the float and the ring contact to be varied. The ring contact is connected by means of leads 89 and 91 with one terminal of the battery 93 (Fig. 2), the other terminal of the battery being connected to an end of each of the solenoids 67. The other ends of the solenoids are respectively connected through switches comprising contacts 95 and cooperating switch arms 97 to the spring contacts 83 and 85, leads 99 connecting the solenoids to the contacts 95. and leads 101 connecting the switch arms 97 to the spring contacts 83 and 85. The switch arms 97 are biased toward the contacts 95 by means of springs 103 and on the drum are adjustable stops 105 which when the drum has moved through a predetermined distance in either direction, that is to say to one or the other of the ends of its travel, move one or the other of the switch arms out of contact with its associated contact 95 so as to deenergize' the solenoid then energized and of rotation of the gravity of the electrolyte increases by reason of an increase inits metalcontent causing the float to rise and bring the ring "contact 81 into contact with the spring contact 83, the right hand solenoid 69 will be energized because the lead 101 connected to the sprin contact 83 is then in communication wit the right hand solenoid by reason of the fact that the left hand switch arm" 97 is in contact with its associatedcontact 95. When the right hand solenoid is thus energized the arms 69 of the reversing switch are moved to their extreme right hand position and establish communication between the line and the terminals of the motor 57 to effect clockwise rotation of the drum 49 and thereby raise the container 31 relatively to the electrolyte. The motor thus energized continues .to rotate the drum until the right hand stop 105 as viewed in Fig. 3 moves the ri ht hand switch arm 97 out of contact wit the associated contact 95 which deener 'zes thefrigh'thand solenoid 69, thus permitting the spring" 71 to move the arms 59 of the reversing-switch into neutral position whereuponthe motor ceases operation. Subsequently when the specific gravity of the electrolyte falls due to a decrease in its metal content and the float descends to bring the ring contact 81 into contact with the sprin contact 85, the left hand solenoid 69 wi be energized because the right hand stop 105 will then be out of contact with the right hand switch arm 97 thus permitting the latter to contact with its associated contact 95.

Although I have described for purposes of illustration one specific embodiment of my invention it is to be understood that I am not limited thereby to its particular mechanical details, but that within the scope of my invention wide deviations may be made therefrom without departing from the spirit of my invention. Claims: I 1. That method of increa-sin the metal content of an electrolyte whic comprises allowing the electrolyte to act on metalbearing material while controlling the rate of solution of metal into the electrolyte by varying both the amounts of soluble material and electrolyte subjected to each other. 2. That method of increasing the metal content of an electrolyte which comprises allowing the electrolyte to act on metalbearing material on which is impressed an electrical potential while controlling the rate of solution of metal into the electrolyte by varying both the amounts of soluble material and electrolyte subjected to each other. 3. That method of increasing the metal combination,

content of an electrolyte which comprises allowing the electrolyte to act\ on metalbearing material while controlling the rate of solution ofmetal into the electrolyte by -efl'ecting movement of the metal-bearing material in and out of the electrolyte.

'4. That method of increasing the metal content of an electrolyte which comprises allowing the electrolyte to act on soluble metal-bearing material on which is impressed an electrical potential while con trolling the rate of solution of metal into the electrolyte by effecting movement of the metal-bearing material in and out of the electrolyte. l

5. Electrolytic apparatus. comprising, in

a cathode, insoluble conductive material constituting an anode, means for passing the electrolyte between said anode and cathode, a body of soluble metal-bearing material for replenishing the electrolyte, means for passing the electrolyte in contact with sai, body of soluble material, and varying both the amount of a rial and amount of electrolyte h other.

6 .=ic apparatus comprising, in combination, a cathode, insoluble conductive material: constituting an anode, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolytebetween said cathode and anode and in cont-act with said soluble material, and means or moving a port-ion of said soluble material in and out of electrolyte.

7. Electrolytic apparatus; comprising, in combination, a cathode, insoluble conductive material constituting an anode, means for passing the electrolyte between said anode and cathode, a body of soluble metal-bearing material ,for replenishing the electrolyte, means for-passing the electrolyte in contact with sai'cl fliiody of soluble material, and

'ineans automatically responsive to changes 11'1" specific: gravity of the electrolyte for vary ng hot-h the amount of soluble material and ainouhtof electrolyte subjected to each other.

8. Electrolytic apparatus comprising, in combination, a cathode, insoluble conductive -material constituting an anode, soluble metal-bearing material for replenishing the electrol te, means for circulating the electrolyte hetween said cathode and anode and in contact with said soluble material, and means automatically responsive to changes in specific gravity of the electrolyte for moving a portion of said soluble anode material in and out of electrolyte.

9. Electrolytic apparatus comprising, in combination, a cathode, insoluble conductive material constituting an anode, soluble metal-bearing material for replenishing the electrolyte, means for circulating theelectrolyte between said cathode and anode and ii [I soluble material, and means comprising a movable container for said soluble material, for varying the ratio of the amount of soluble material to the amount of electrolyte subjected to each other.

\10. Electrolytic ap aratus comprising, in combination, a catho e, insoluble conductive material constituting an anode, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte between said cathode and anode and in contact with said soluble material, a movable container for the soluble material, and means for raising and lowering said container relatively to the electrolyte.

11. Electrolytic ap aratus comprising, in combination, a catho e, insoluble conductive material constituting an anode, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte between said cathode and anode and in contact with said soluble material, a conduit means through which the electrolyte circulates, container means for said soluble material in said conduit means, and means for operatively effecting relative motion between said conduit means and container means for varying the amount of soluble material subjected to the action of the electrolyte.

12. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble n1eta1 bearing material for replenishing the electrolyte, means for flowing the electrolyte in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other.

13. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for flowing the electrolyte in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other comprising means for moving a portion of the soluble material in and out of the electrolyte.

14. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble in contact with said metal-bearing material for replenishing the electrolyte, means for flowing the electrolyte in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other comprising means for moving the soluble material.

15. Electrolytic ap aratus comprising, in combination, a catho e for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for circulating the'electrolyte past said cathode and in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each 16. Electrolytic apparatus comprisin in combination, a cathode for deposition t ereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte past said cathode and in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other comprising means moving a portion of said soluble material in and out of the electrolyte.

17. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte past said cathode and in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other comprising means for moving the soluble material and electrolyte relatively to each other.

.18. Electrolytic ap aratus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte past said cathode and in contact with said soluble material, and means for moving said soluble material in and out of the electrolyte.

In testimony whereof, I have signed my name to this specification.

MATTHEW M. MERRITT.

,in contact with said soluble material, and means comprising a movable container for said soluble material, for varying the ratio of the amount of soluble material to the amount of electrolyte subjected to each other.

10. Electrolytic ap aratus comprising, in combination, a catho e, insoluble conductive material constituting an anode, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte between said cathode and anode and in contact with said soluble material, a movable container for the soluble material, and means for raising and lowering said container relatively to the electrolyte.

11. Electrolytic ap aratus comprising, in combination, a catho e, insoluble conductive material constituting an anode, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte between said cathode and anode and in contact with said soluble material, a conduit means through which the electrolyte circulates, container means for said soluble material in said conduit means, and means for operatively effecting relative motion between said conduit means and container means for varying the amount of soluble material subjected to the action of the electrolyte.

12. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for flowing the electrolyte in contact with said soluble material, and means for varying both the amount of soluble material. and amount of electrolyte subjected to each other.

13. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for flowing the electrolyte in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other comprising means for moving av portion of the soluble material in and out of the electrolyte.

14. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble Certificate of metal-bearing material for replenishing the electrolyte, means for flowing the electrolyte in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other comprising means for moving the soluble material.

15. Electrolytic ap aratus comprising, in combination, a catho e for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte past said cathode and in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other.

16. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte past said cathode and in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other comprising means moving a portion of said soluble material in and out of the electrolyte.

17. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte past said cathode and in contact with said soluble material, and means for varying both the amount of soluble material and amount of electrolyte subjected to each other comprising means for moving the soluble material and electrolyte relatively to each other.

18. Electrolytic apparatus comprising, in combination, a cathode for deposition thereon of metal from the electrolyte, soluble metal-bearing material for replenishing the electrolyte, means for circulating the electrolyte past said cathode and in contact with said soluble material, and means for moving said soluble material in and out of the electrolyte.

In testimony whereof, I have signed my name to this specification.

MATTHEW M. MERRITT.

Correction.

It islhereb certified that in Letters Patent No. 1,601,692, granted September 28, 1926, upon 1; e application of Matthew M. Merritt, of Middleton, Massachusetts, for an improvement in Electrolytic Deposition of Metals, an error appears in the printed specification requiring correction as follows: Page 3, line 99, claim"6, for the word or read for; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 19th day of October, A. D. 1926.

[sEAn] WM. A. KINNAN,

Acting Commissioner of Patents.

Certificate of Correction.

It isihereb certified that in Letters Patent No. 1,601,692, granted September 28,

1926, upon t e application of Matthew M. Merritt, of Middleton, Massachusetts for an improvement in Electrolytic Deposition of Metals, an error appears in the printed specification requiring correction as follows: Page 3, line 99, claim 6, for the Word or read for, and that the said Letters Patent should be read with this correction therein that the same may conform to the record of t case in the Patent Office.

Signed and sealed this 19th day of October, A. D. 1926.

[SEAL] WM. A. KINNAN,

Acting Commissioner of Patents. 

